William Warren Reinhart was born in July 1879 to Caleb and Clara (Downer) Reinhart in Washington State. Caleb Reinhart was from an established Olympia, WA family. Caleb was born in 1856 to Stephen D. and Sarah (Cock) Reinhart in Olympia, Thurston County, WA. By the time of Stephen's death in 1901, he had been involved in the development of Washington State since his arrival about 1852. Stephen had lived and worked in Olympia; moved to Oregon and California due to his wife's health; returned to Whatcom County, WA and farmed after his wife's death; became a State Senator serving two sessions. Caleb, Stephen's son, had become a prominent citizen of Olympia, WA. Caleb married Clara Downer, a native of Oregon, in 1877. They had six children. When Caleb had received the appointment of Clerk of the Supreme Court in 1891, he and his family moved to Olympia, WA. Caleb studied law and was admitted to the Bar in 1895 although he never practiced law. Caleb served three terms as mayor of Olympia. Caleb participated in the organization of the Washington State National Guard and was named Captain. He was president of the Olympia National Bank and had many business interests. In 1899 William, Caleb's son, was attending the State University when the call for volunteers for the Spanish American War. He left school and enlisted as a private in Company "G" of the First Regiment of Washington Volunteers. William was mustered in as a Corporal because he had been a member of the University Cadets and had military experience. He sailed for Manila, Philippines in October 1898. While he was in the Philippines, he wrote his father and asked him what the chances might be of him receiving a commission at West Point. There were a couple of letters trying to secure a cadetship for him at West Point. It doesn't appear that he secured a commission at West Point. By 1900 William had returned home to Olympia, WA. In 1910, William was living and working in Thurston County, WA. It is believed that William moved to Venezuela to live because he may have contracted a tropical disease while in the Philippines. It is believed that he passed away while he was in Venezuela in 1926.
The First Washington Infantry, U.S. Volunteers, was organized in mid-1898 to fulfill the state's responsibility to provide 125,000 volunteers to fight in the Spanish-American War. Shortly after the U.S. declared war against Spain, President William McKinley called for each state to provide 125,000 men to serve a minimum of two years. The state of Washington organized its quota of men into one infantry regiment composed of several companies. These included two from Seattle, two from Spokane, and one each from Tacoma, Walla Walla, North Yakima [later renamed Yakima], Waitsburg, Ellensburg, Centralia, Dayton, and Vancouver. Under the command of Colonel John H. Wholley, the First Washington Infantry's twelve companies assembled together and were mustered into U.S. military service at Camp John R. Rogers, near Tacoma, on May 1, 1898. On May 10, the first battalion, consisting of companies A," "B," "D," and "E," left Tacoma under sail for San Francisco to await further orders and practice drills. The second battalion, consisting of companies "F," "G," "I," and "L," left Camp Rogers on May 15 to join the first battalion at San Francisco's Camp Merritt. The third battalion, consisting of companies "C," "H," "K," and "M," proceeded to the Vancouver Barracks, Vancouver, Washington, on May 24, and like the other battalions its devoted the next several weeks to field drills. There was no Company "J." By late July, the third battalion rejoined its fellow battalions in San Francisco. By late October, the Washington volunteer regiment had embarked steamers for Manila, Philippine Islands. The First Washington Infantry, U.S.V., participated in numerous battles with Filipino insurgents throughout the first half of 1899. By late August, Colonel Wholley received orders to return to the States, arriving in San Francisco in early October 1899. Washington Governor Rogers and several delegates from the state met the men at the docks to celebrate their victories and their safe return home. The volunteers were mustered out on October 31, 1899.
From the description of William W. Reinhart's correspondence during the Spanish-American War, 1898-1900. (Washington State Library, Office of Secretary of State). WorldCat record id: 191914311